# Graphical

### Tk:

```ruby
var tk = require('Tk')
var main = %O<MainWindow>.new
main.Button(
    '-text'    => 'Goodbye, World!',
    '-command' => 'exit',
).pack
tk.MainLoop
```

### Gtk2:

```ruby
var gtk2 = require('Gtk2') -> init
 
var window = %O<Gtk2::Window>.new
var label  = %O<Gtk2::Label>.new('Goodbye, World!')
 
window.set_title('Goodbye, World!')
window.signal_connect(destroy => { gtk2.main_quit })
 
window.add(label)
window.show_all
 
gtk2.main
```

### Gtk3:

```ruby
use('Gtk3 -init')

var gtk3   = %O'Gtk3'
var window = %O'Gtk3::Window'.new
var label  = %O'Gtk3::Label'.new('Goodbye, World!')

window.set_title('Goodbye, World!')
window.signal_connect(destroy => { gtk3.main_quit })

window.add(label)
window.show_all

gtk3.main
```


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